Suspension fork for bicycles

Abstract

A bicycle fork for interconnecting a bicycle wheel to a bicycle frame. The bicycle fork includes first and second leg members slidably engaged with each other, an elastomer spring for providing a biasing force when the leg members are compressed toward each other, and a damping mechanism for providing a damping force to resist relative movement of the leg members. The damping mechanism provides expansive damping greater than compressive damping and further allows for adjustment of the expansive damping to fine tune the suspension characteristics of the bicycle fork.

What is claimed is: 
     
       1. A bicycle fork for interconnecting a bicycle wheel to a bicycle frame, said bicycle fork comprising: at least one leg assembly comprising first and second leg members slidably engaged with each other, said at least one leg assembly being compressible by relative movement of said first and second leg members toward each other, and being expandable by relative movement of said first and second leg members away from each other;   biasing means for providing a biasing force when said leg assembly compresses, said biasing means including at least one elastomer; and   at least one positioning member positioned adjacent to said at least one elastomer and including a raised portion extending toward said at least one elastomer on the perimeter thereof for facilitating maintenance of said at least one elastomer in alignment with said leg members.   
     
     
       2. A bicycle fork, as recited in claim 1, wherein said raised portion comprises an upstanding annular ridge extending substantially around the circumference of at least part of said at least one elastomer. 
     
     
       3. A bicycle fork, as recited in claim 1, wherein said at least one elastomer comprises at least two elastomers, and wherein said at least one positioning member is positioned between said at least two elastomers. 
     
     
       4. A bicycle fork, as recited in claim 3, wherein said raised portion comprises an upstanding annular ridge, a first part of said ridge extending toward one of said at least two elastomers and a second part of said ridge extending toward another of said at least two elastomers. 
     
     
       5. A bicycle fork, as recited in claim 3, wherein said at least two elastomers comprises a plurality of pairs of adjacent elastomers, and wherein said at least one positioning member comprises a positioning member positioned between each of said pairs of adjacent elastomers. 
     
     
       6. A bicycle fork, as recited in claim 1, wherein said at least one positioning member and said at least one elastomer each include a bore extending therethrough, and wherein said bicycle fork further comprises an elastomer rod positioned through said bores in said at least one positioning member and said at least one elastomer. 
     
     
       7. A bicycle fork, as recited in claim 6, wherein said bores are substantially centrally located on said at least one positioning member and said at least one elastomer. 
     
     
       8. A bicycle fork, as recited in claim 1, further comprising a compression rod having a first end interconnected with one of said leg members and a second end engaged with said at least one elastomer. 
     
     
       9. A bicycle fork, as recited in claim 8, further comprising a compression flange positioned on said second end of said compression rod in engagement with said at least one elastomer. 
     
     
       10. A bicycle fork, as recited in claim 9, wherein said compression flange includes a protruding portion extending toward said elastomer on the perimeter thereof for facilitating maintenance of said elastomer in alignment with said first and second leg members. 
     
     
       11. A bicycle fork, as recited in claim 10, wherein said protruding portion comprises an upstanding annular protrusion extending substantially around the circumference of said at least one elastomer. 
     
     
       12. A bicycle fork for interconnecting a bicycle wheel to a bicycle frame, said bicycle fork comprising: at least one leg assembly comprising first and second leg members slidably engaged with each other, said at least one leg assembly being compressible by relative movement of said first and second leg members toward each other, and being expandable by relative movement of said first and second leg members away from each other, at least one of said first and second leg members having a tapered wall thickness, wherein the first tube slides within the second tube, and wherein the first tube has the tapered wall thickness; and   biasing means for providing a biasing force when said leg assembly compresses.   
     
     
       13. A bicycle fork, as recited in claim 12, wherein the first tube has a wall thickness which is greater at a top portion than at a bottom portion. 
     
     
       14. A bicycle fork for interconnecting a bicycle wheel to a bicycle frame, said bicycle fork comprising: at least one leg assembly comprising first and second leg members slidably engaged with each other, said at least one leg assembly being compressible by relative movement of said first and second leg members toward each other, and being expandable by relative movement of said first and second leg members away from each other;   biasing means for providing a biasing force when said leg assembly compresses, said biasing means comprising an elastomer and being contained within said first leg member; and   first means for aligning said biasing means within said first member; and   second means, separate from said first means, for aligning said biasing means within said first leg member, wherein said first means comprises an elastomer rod which extends through said elastomer and said second means comprises a generally cup-shaped member which receives an end portion of said elastomer.   
     
     
       15. A bicycle fork, as recited in claim 14, wherein said first means engages an internal portion of said elastomer and said second means engages an external portion of said elastomer. 
     
     
       16. A bicycle fork, as recited in claim 14, wherein said biasing means further comprises a plurality of said elastomers and at least one of said second means is positioned between each adjacent pair of said elastomers. 
     
     
       17. A bicycle fork, as recited in claim 16, wherein each said second means comprises two generally cup-shaped portions extending in opposite directions, each of said cup-shaped portion receiving at least part of one of said adjacent pair of said elastomers. 
     
     
       18. A bicycle fork for interconnecting a bicycle wheel to a bicycle frame, said bicycle fork comprising: at least one leg assembly comprising first and second leg members slidably engaged with each other, said at least one leg assembly being compressible by relative movement of said first and second leg members toward each other, and being expandable by relative movement of said first and second leg members away from each other;   biasing means for providing a biasing force when said leg assembly compresses, said biasing means comprising a plurality of elastomers contained within said first leg member; and   first means for aligning said biasing means within said first member; and   second means, separate from said first means, for aligning said biasing means within said first leg member, wherein at least one of said second means is positioned between each adjacent pair of said elastomers and wherein each said second means comprises two generally cup-shaped portions extending in opposite directions, each of said cup-shaped portions receiving at least part of one of said adjacent pair of said elastomers.